Stone Dragons
From WikiRaider
The Stone Dragons are pick-ups found in Tomb Raider II. These are secret items and they come in three different forms:
You will find one of each secret in every level of the game.
By collecting all three dragons in a level, you will get a reward like Ammo for the Shotgun, Automatic Pistols, Uzis, Grenade Launcher or Harpoon Gun.